Separable pole clamp



Oct' 9, 195l E. w. RIEMENSCHNEIDER E-r/u. 2,570,985

SEPARABLE POLE CLAMP Filed June 28, 1948 l MM WM A TTORNE YS PatentedOct. 9, 1951 SEPARABLE POLE CLAMP Edmund W. Riemenschneider and WilburC. An-

derson, Canton, Ohio, assignors to The, Union A Metal ManufacturingCompany, Canton, Ohio,

a corporation of Ohio Application June 28, 1948, Serial No. i-204 3Claims. 1

The invention relates generally to clamps for supporting lateral arms orbrackets on lighting poles and the like, and more particularly to aseparable clamp which will wrap around the pole to adjust itself tovarious pole diameters within a limited range.

There` are certain prior separable or two-part pole clamps which aresubstantially rigid and which have out/turned cantilever ears for engageing the clamping bolts, and when these clamps are. drawn together toclamp around various sizes of poles the forcel is transmitted from thebolts to the clamp at the bases ofthe ears. The result is that the*clamps tend to dig into the pole at` those points, and the ears willbend before sufcient wrapping contact of the clamp with the pole isaccomplished,

Because of these point contacts between such. prior clamps and thepole,` the clamp is'apt to slip upor down or around the pole, and theclamp does not have maximum strength because the? clamping force is nottransmitted substantially in awrapping direction, i. e.circumferentially of the pole, but is concentrated in particular points.

While certain prior clamps have had ears formed by bending the ends ofthe clamp into a. triangular shape., some of such ears have eX- tendedtoo far around the periphery of the clamp with the result that unlesscurved clamping bolts are used, the bolts do not lie. closely enough tothe. pole and the clamp. does not t a range of pole sizes because'of thelarge amount of Variation in the radial distance of the bolts from thepole.r In other prior clamps having these triangular ears, the ears havenot extended far enough around the periphery of the clarnptol give fullstrength in a wrapping or circumferential direction when used withdiierent pole sizes,I because the bolts have caused rthe ears to rockaround their front ends as a fulcrum and thus pull the clamp away fromthe pole at the base of the ear.

It is a general object of the present invention to provide a` noveltwo-part clamp which overcomes all of the foregoing disadvantages ofprior clamps.

Another and more specific object is to provide a novel two-part clampwhich is adapted to wrap around and hug poles of dierent sizes within asubstantial range, to give full surface contact between the clamp andpole.

.Another object' is to provide a novel two-part clamp in which theclamping boltsexerti their force circumferentially of the clamp to givemaximum strength with minimum material.

A further object is to provide a novel two-part; clamp in which the@1amping;,earsare.ccinstructesl to. use straight bolts which lieelose tothe pole throughout a substantial range of polev sizes.

A still further object is to provide a novel and improved vtwo-partclamp which is simple and inexpensive to make, and which is. easilyapplied without special tools.

These and other objects are. accomplished by the parts, constructions,arrangements, and combinations which comprise the present inventionl,the nature of which is set for-th lin the following general statement,and a preferred embodiment of which is set forth in the followingdescription and illustrated in the accompanying drawings, and which isparticularly and distinctly pointed out and set forth in the appendedclaims forming part hereof.

In general terms, the novel two-part clamp comprising the presentinvention preferably in-A cludes two clamping` bands of resilientmaterial for wrapping around a range of sizes. of poles, thel peripherallength of each band being slightly less than one-half of the smallestpole circumferencev within the range, each band having itsI ends bentrearwardly outward and thenY inclined inward to form a. triangular ear,the shape ofthe` triangle being substantially equilateral, the front.side of theear being slotted to receive a straight clamping bolt atvarying radial distances `from the pole, and the rear part of the earbeing secured to the peripheral part of the band and havinga hole forreceiving the clamping bolt.

Referring to the drawingforming part hereof in which a preferredembodiment of the invention is shown-by Way'of; examplel AFigure 1v is aplan view oi the improved clamp secured around a pole, the pole beingShown in section and the clamp in elevation;

Fig. 2 is a fragmentary plan sectional view through the clamp;

Fig. 3 is a frontA elevation of the clamp shown in Fis. 1;V

Fig; 4 is a side elevation thereof; and

Fig.A 5 is a fragmentary enlarged view similar to Fig. 1 showing twopositions of the improved clamp secured on two. different sizes ofApoles.

Similar numerals refer to similar parts throughoutthe several views offthe. drawing.

Theclamp shown in the drawing includes two parts orhands. 6 and 'l andthe bands areof such Widthsas to-'requirevfgour clamping bolts 8 fordrawing them togetheraround a y,circular pole 9. it will be understoodthat it isv within the scope of the invention to provide narrow clampingbands which require only two bolts for clamping them around, aP016;the'desisnand,construction or the clamping bands and their earsbeing otherwise the same as those shown and described herein.

For supporting a lateral arm on the improved clamp, the clamping band 'Iis provided with a supporting boss indicated generally at I, which isadapted to be received in a complementary socket in the end of the armfor solidly supporting the arm on the clamp. Obviously, other ways ofattaching lateral arms or brackets to the clamp can be employed withoutdeparting from the scope of the invention as defined in the claims.

Each of the bands and 'i has an arcuate peripheral body portion whichis, preformed to conform substantially to the circumference of a polehaving a diameter substantially equal to or slightly less than thelargest diameter pole in the range of diameters for which the clamp isdesigned. Moreover, the inside peripheral length of each band is madeslightly less than one-half the circumference of the smallest pole insaid range, so that when the two bands are clamped around the smallestpole, their ends will not abut each other.

If, for example, the clamp is designed to t a range of poles of 4%diameter to 51/4 diameter, the inner radius of each of the bands 6 and Iis made to be about 21% so that the curvature of the bands correspondsto the circumference of a pole 51/8 in diameter, and the peripherallength of each band is slightly less than one-half the circumference ofa 41% diameter pole.

The material of the bands is a standard low carbon, low alloy, highstrength steel plate of 1% thickness, which we have found in actualpractice will wrap around poles of flg" diameter and upwards and givemaximum strength to the clamp. The clamps may be made in several sizesto t ranges of pole diameters different from that given above, but ineach case the curvature of the bands is preformed to conform to sub--stantially the largest diameter pole within the range, and the innerperipheral length oi each band is slightly less than one-half of theouter circumference of the smallest diameter pole in the range.

The ears for engaging the clamping bolts 8 are preferably formed byinclining the end portion of each band outwardly and rearwardly to forma leg II and then bending the outer end inwardly to form a rear leg i2inclined to the leg II, so that the legs II and I2 are at substantiallyequal angles to the intervening portion of the band 6a or la, and sothat they form a substantially equilateral triangle with the band. Theinner end of each leg I2 is secured to the band at I2', as by welding.

The outer'leg I I of each ear is provided with a closed slot I3extending substantially radially throughout the length of the leg I I,and the slot I3 is adapted to receive a straight clamping bolt B atdifferent positions radially of the ears for accommodating differentsizes of poles 9, as in.v dicated in Fig. 5. The rear legs I2 of eachear are provided with bolt holes I4 aligned with the slots I3, and theholes I4 are preferably square for receiving the squared Shanks I5 ofcarriage bolts 8,. The width of each leg I2 from its end I2' to itsconnection with leg Il is ample to support the head i6 or nut 8 of abolt.

In Figs. l through 4, the improved clamp is shown in position around apole of a larger size diameter within its range, so that the clampingbands 6 and 'I are spread apart at the ears to a position similar to thedot-dash position shown in Fig. 5. When the same clamp is drawn to- 4gether about a smaller diameter pole within its range, the ears assumethe full line position shown in Fig. 5.

In Figs. 1 and 2, the clamping bolts are seated at the inner ends of theslots I3 and lie closely adjacent to the outer circumference of the pole9. When the clamp is drawn together around a smaller pole by tighteningthe nuts 8', the ears are drawn closer together as shown in the fullline position of Fig. 5, and the clamping bolts move slightly outwardlyin the slots I3, but in each case the bolts lie quite close to the poleso that the force exerted by the bolts is transmitted to the clampingbands in a circumferential direction directly around the bands so as tocause them to wrap around and closely hug the pole.

If the ears of the clamping bands were formed so that the leg I2 wasconnected to the periphery of the band at a greater distance from thefront end Il of the ear, the force transmitted from the bolts would beslightly more directly around the band, but the bolt head and nut wouldbe moved inwardly of the pole circumference so as to require a curvedbolt to accommodate a range of pole sizes.

By constructing the ears so that the legs I I and I2 and the bandportions 6a or la form substantially an equilateral triangle, we havefound that practically the full strength of the band is obtained for asubstantial range of pole diameters while using straight bolts. We havefound that for various ranges of pole diameters between about 41%" and9%", a standard diameter carriage bolt will give the necessary tensilestrength to insure wrapping the 1% bands around said poles.

The design and construction of the novel clamp provides for obtainingthe full strength of the clamp in a circumferential direction around thepole within a range of pole sizes, Awithout causing the ears to bend orrock and dig into the pole, and without causing pulling away of theclamp at any point around the pole. We have tested the improved clamp incomparison with standard rigid clamps of substantially equal size andthe same material but of slightly greater thickness, and find that thepresent clamp will resist a lateral pull of 15,000 pounds as against4,500 pounds for the rigid clamp. an up and down pull of over 2,000pounds as against 500 pounds for the rigid clamp and a torsional pull of15,000 inch pounds as against 3,000 inch pounds for the rigid clamp.

The improved clamp is simple and inexpensive to make, and easily appliedto or removed from a pole, without requiring special tools.

InY the foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchwords are used for descriptive purposes herein and are intended to bebroadly construed.

Moreover, the embodiment of the improved construction illustrated anddescribed herein is by way of example, and the scope of the presentinvention is not limited to the exact details vof construction. l

Having now described the invention, the construction, the operation anduse of a preferred embodiment thereof, and the advantageous new anduseful results obtained thereby; the new and useful constructions, andreasonable mechanical equivalents thereof obvious to those skilled inthe art, are set forth in the appended claims.

We claim:

1. A separable pole clamp for wrapping around a range of pole diametersincluding two arcuate clamp parts of semi-flexible material, each parthaving a peripheral length slightly less than one-half the circumferenceof the smallest pole diameter in said range, each part having each ofits end portions inclined rearwardly outward and then inwardly in twolegs forming substantially an equilateral triangle with the interveningperipheral portion of the clamp part, the front leg being slottedradially of the clamp for receiving a straight clamping bolt atdifferent radial positions, and the rear leg having a closed bolt slotand its inner edge secured to the peripheral portion of the clamp part.

2. A separable pole clamp for wrapping around a range of pole diametersincluding two arcuate clamp parts of semi-flexible material, each parthaving a peripheral length slightly less than one-half the circumferenceof the smallest pole diameter in said range, each part having each ofits end portions inclined rearwardly outward and then inwardly in twolegs forming substantially an equilateral triangle with the interveningperipheral portion of the clamp part, the front leg having a closed slotextending substantially radial of the clamp for receiving a straightclamping bolt at diierent radial positions, and

the rear leg being secured to the clamp part and having a bolt holealigned with said slot.

3. A separable pole clamp including two arcuate steel clamping bands ofsuch thickness and resilience as to flexibly wrap under tension around apole, each band having a peripheral length slightly less than one-halfthe circumference of the pole, each band having an ear at each endformed of two connected legs disposed at substantially equal angles tothe band and forming a substantially equilateral triangle with theintervening portion thereof, the front leg being slotted radially andsecured at its inner edge to the band and the rear leg being secured atits inner edge to the band and having an aligned bolt hole for receivinga straight clamping bolt at diierent radial positions.

EDMUND W. RIEMENSCHNEIDER. WILBUR C. ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS HOSSfeld Oct. 11, 1932

